This is a proposal for the continued participation of Children's Memorial Hospital (CMH) and its affiliates in the program of cooperative in the program of cooperative clinical trials of the Pediatric Oncology Group (POG). This program provides the mechanism for accrual of eligible patients to an array of therapeutic and ancillary protocols aimed at improving the outcome for children with cancer through multi-disciplinary programs in the areas of pediatric oncology, radiation therapy, surgery, pathology, nursing, supportive care, diagnostic imaging, and data management. This proposal for participation of CMH and its affiliates (Rush-Presbyterian St. Luke's Medical Center (RPSLMC), Cook County Hospital (CCH), and Christ Hospital (CH)] will ensure access of the majority of children diagnosed with malignancies in the greater Chicagoland area to clinical protocols of the POG. The proposal will furthermore provide for the mechanism for attendance and major participation of investigators in group meetings, scientific and developmental activities, committees, specific protocols, administrative and other clinical research activities for the Group.